94f0cf0ef8
* fix: remove isHidden key from tool template * fix: removed isHidden key from English challenges * fix: remove isHidden key from Chinese challenges
6.7 KiB
6.7 KiB
id, title, challengeType
| id | title | challengeType |
|---|---|---|
| 5d8a4cfbe6b6180ed9a1ca1d | Part 64 | 0 |
Description
Next, chain the enter() function to the selection.
The enter function identifies elements that need to be added when the data array is longer than the selection array. This is why you wanted the selectAll to be an empty array before.
In this case, the twitter-circles selection has a length of 0, and the data array has a length of 9. So nine elements will be added when you use append in the next step.
Instructions
Tests
tests:
- text: test-text
testString: assert(/\.data\(data\)\s*\.enter\s*\(\s*\)/g.test(code));
Challenge Seed
<script>
const data = [
{ year: 2012, followers: { twitter: 2594, tumblr: 401, instagram: 83 }},
{ year: 2013, followers: { twitter: 3049, tumblr: 440, instagram: 192 }},
{ year: 2014, followers: { twitter: 3511, tumblr: 415, instagram: 511 }},
{ year: 2015, followers: { twitter: 3619, tumblr: 492, instagram: 1014 }},
{ year: 2016, followers: { twitter: 4046, tumblr: 543, instagram: 2066 }},
{ year: 2017, followers: { twitter: 3991, tumblr: 701, instagram: 3032 }},
{ year: 2018, followers: { twitter: 3512, tumblr: 1522, instagram: 4512 }},
{ year: 2019, followers: { twitter: 3274, tumblr: 1989, instagram: 4715 }},
{ year: 2020, followers: { twitter: 2845, tumblr: 2040, instagram: 4801 }}
];
</script>
<script>
const svgMargin = 70,
svgWidth = 700,
svgHeight = 500,
twitterColor = '#7cd9d1',
tumblrColor = '#f6dd71',
instagramColor = '#fd9b98';
const lineGraph = d3.select('.dashboard')
.append('svg')
.attr('width', svgWidth)
.attr('height', svgHeight);
const yScale = d3.scaleLinear()
.domain([0, 5000])
.range([svgHeight - svgMargin, svgMargin]);
const xScale = d3.scaleLinear()
.domain([2012, 2020])
.range([svgMargin, svgWidth - svgMargin]);
const yAxis = d3.axisLeft(yScale)
.ticks(6, '~s');
const xAxis = d3.axisBottom(xScale)
.tickFormat(d3.format(''))
.tickPadding(10);
lineGraph.append('g')
.call(yAxis)
.attr('transform', `translate(${svgMargin}, 0)`)
.style('font', '10px verdana');
lineGraph.append('g')
.call(xAxis)
.attr('transform', `translate(0, ${svgHeight - svgMargin})`)
.selectAll('text')
.style('transform', 'translate(-12px, 0) rotate(-50deg)')
.style('text-anchor', 'end')
.style('cursor', 'pointer')
.style('font', '10px verdana')
const twitterLine = d3.line()
.x(d => xScale(d.year))
.y(d => yScale(d.followers.twitter));
lineGraph.append('path')
.attr('d', twitterLine(data))
.attr('stroke', twitterColor)
.attr('stroke-width', 3)
.attr('fill', 'transparent');
const tumblrLine = d3.line()
.x(d => xScale(d.year))
.y(d => yScale(d.followers.tumblr));
lineGraph.append('path')
.attr('d', tumblrLine(data))
.attr('stroke', tumblrColor)
.attr('stroke-width', 3)
.attr('fill', 'transparent');
const instagramLine = d3.line()
.x(d => xScale(d.year))
.y(d => yScale(d.followers.instagram));
lineGraph.append('path')
.attr('d', instagramLine(data))
.attr('stroke', instagramColor)
.attr('stroke-width', 3)
.attr('fill', 'transparent');
lineGraph.selectAll('twitter-circles')
.data(data)
</script>
Before Test
<!DOCTYPE html>
<html>
<head>
<title>D3 Dashboard</title>
<style>
body {
background-color: #ccc;
padding: 100px 10px;
}
.dashboard {
width: 980px;
height: 500px;
background-color: white;
box-shadow: 5px 5px 5px 5px #888;
margin: auto;
display: flex;
align-items: center;
}
</style>
</head>
<body>
<div class="dashboard"></div>
</body>
</html>
Solution
<script>
const data = [
{ year: 2012, followers: { twitter: 2594, tumblr: 401, instagram: 83 }},
{ year: 2013, followers: { twitter: 3049, tumblr: 440, instagram: 192 }},
{ year: 2014, followers: { twitter: 3511, tumblr: 415, instagram: 511 }},
{ year: 2015, followers: { twitter: 3619, tumblr: 492, instagram: 1014 }},
{ year: 2016, followers: { twitter: 4046, tumblr: 543, instagram: 2066 }},
{ year: 2017, followers: { twitter: 3991, tumblr: 701, instagram: 3032 }},
{ year: 2018, followers: { twitter: 3512, tumblr: 1522, instagram: 4512 }},
{ year: 2019, followers: { twitter: 3274, tumblr: 1989, instagram: 4715 }},
{ year: 2020, followers: { twitter: 2845, tumblr: 2040, instagram: 4801 }}
];
</script>
<script>
const svgMargin = 70,
svgWidth = 700,
svgHeight = 500,
twitterColor = '#7cd9d1',
tumblrColor = '#f6dd71',
instagramColor = '#fd9b98';
const lineGraph = d3.select('.dashboard')
.append('svg')
.attr('width', svgWidth)
.attr('height', svgHeight);
const yScale = d3.scaleLinear()
.domain([0, 5000])
.range([svgHeight - svgMargin, svgMargin]);
const xScale = d3.scaleLinear()
.domain([2012, 2020])
.range([svgMargin, svgWidth - svgMargin]);
const yAxis = d3.axisLeft(yScale)
.ticks(6, '~s');
const xAxis = d3.axisBottom(xScale)
.tickFormat(d3.format(''))
.tickPadding(10);
lineGraph.append('g')
.call(yAxis)
.attr('transform', `translate(${svgMargin}, 0)`)
.style('font', '10px verdana');
lineGraph.append('g')
.call(xAxis)
.attr('transform', `translate(0, ${svgHeight - svgMargin})`)
.selectAll('text')
.style('transform', 'translate(-12px, 0) rotate(-50deg)')
.style('text-anchor', 'end')
.style('cursor', 'pointer')
.style('font', '10px verdana')
const twitterLine = d3.line()
.x(d => xScale(d.year))
.y(d => yScale(d.followers.twitter));
lineGraph.append('path')
.attr('d', twitterLine(data))
.attr('stroke', twitterColor)
.attr('stroke-width', 3)
.attr('fill', 'transparent');
const tumblrLine = d3.line()
.x(d => xScale(d.year))
.y(d => yScale(d.followers.tumblr));
lineGraph.append('path')
.attr('d', tumblrLine(data))
.attr('stroke', tumblrColor)
.attr('stroke-width', 3)
.attr('fill', 'transparent');
const instagramLine = d3.line()
.x(d => xScale(d.year))
.y(d => yScale(d.followers.instagram));
lineGraph.append('path')
.attr('d', instagramLine(data))
.attr('stroke', instagramColor)
.attr('stroke-width', 3)
.attr('fill', 'transparent');
lineGraph.selectAll('twitter-circles')
.data(data)
.enter()
</script>